The invention relates to a security document, in particular a banknote or an identity card, which has a carrier and a multi-layer flexible film body which is applied to the carrier and which provides one or more optical security features.
In regard to the possible options afforded by modern colour copiers and other reproduction systems, there is a need for security documents to be provided with security features which on the one hand make it more difficult to produce a forgery using apparatuses of that kind and which on the other hand are easily and clearly recognisable for a lay person.
For that purpose it is known for security elements in the form of security threads to be incorporated into value-bearing documents, the arrangement being such that the thread is exposed region-wise at the surface and thus the optical security elements which are incorporated into the thread, for example holograms or partial demetallisations, can be checked by the person viewing same.
It is further known from EP 1 134 694 A1 for an electronic circuit to be printed on a sheet or strip of paper, the circuit comprising organic semiconductor material and being connected to a metal strip of a banknote by way of a conductor path. In that case the electronic circuit is not based on electronic components made up from usual semiconductor materials, but on organic field effect transistors using polymer semiconductor technology. In that case the metal strip serves as an antenna by way of which communication is possible between the semiconductor circuit and a corresponding evaluation circuit. In that way the electronic circuit can serve to detect forgeries while in addition it is made possible to detect the location of the document.